Ocimum Basilicum Leaf Extract

Ocimum basilicum (basil) leaf extract is a botanical antioxidant/fragrance-adjacent ingredient whose composition often includes sensitizing aromatic constituents (e.g., linalool, eugenol/estragole depending on extract), making irritation/allergic contact dermatitis a clinically recognized risk in reactive skin. While typically used at low concentrations, leave-on exposure and cumulative use with other actives can meaningfully increase stinging, erythema, or eczema flares in sensitive populations. Given the variability of extracts and documented sensitization potential of basil-derived aromatics, I score it as a notable risk requiring caution and patch testing in eczema-prone users. Safety Notes: In mass-market leave-on and rinse-off skincare, Ocimum Basilicum (Basil) Leaf Extract is commonly used as a low-level “botanical support” ingredient (often within a broader plant-extract blend) at ~0.001–0.1%, driven by cost, color/odor control, and irritation/sensitization considerations. Higher-strength consumer products positioned as botanical/clarifying/antioxidant treatments and some natural/indie lines can use single extracts at ~1–5% (sometimes higher as a supplied dilution, but ~5% active extract in the finished product is a practical upper end for stability and sensorial limits). Rinse-off formulas can tolerate the upper portion of the range more easily, while leave-on products tend to cluster toward the lower end due to potential fragrance/allergen components and sensitization risk.